The drush command '@project_test_devshop provision-devshop-create' could not be found.
Could not find a Drupal settings.php file at ./sites/default/settings.php.

Are my Devshop modules bad installed or is it a problem with BOA ?

When I try to pull codes on a site, I have the following errors also:

The drush command 'provision-devshop-pull' could not be found.

These issues are always in my objective of load-balancing BOA. I will use an external load-balancer but I want to use a git system to have the same code in the website instance in each BOA server into the system.
For instance:

server1: barracuda
->o1
->site.server1.net the site I want to load-balance, I think a DevShop project pulling from the Devshop project server
server2: barracuda
->o1
->site.server2.net the same site as above in the load-balancer, the same Devshop Project also pulling from the Devshop project server

Or it means that you are trying to use extension designed to work with Aegir 1.x, while BOA uses Aegir 2.x. I believe this is the real source of the problem, but we can't do anything to fix this, until Devshop will support Aegir 2.x